Defining Border Security Key to Talks

GOP Senators Fear a New Illegal Influx, and Democrats Worry a Vague Bill Would Delay Citizenship

By

Laura Meckler

Updated Feb. 1, 2013 8:39 p.m. ET

WASHINGTON—How to determine whether the U.S. border with Mexico is secure has emerged as a central battle among senators writing an overhaul of immigration laws.

The senators working on the legislation, four Democrats and four Republicans, say that many of the 11 million people living in the nation illegally should have the chance to become U.S. citizens. But their proposal says that opportunity is "contingent on securing the...